The present invention relates to compound miter saws or other power operated equipment or machinery utilizing a cutter for performing working operations on a workpiece. More particularly, the present invention relates to improvements in the locking mechanism for the bevel adjustment for such power operated equipment, with the locking mechanism having an adjustable cam lock arrangement for locking the bevel pivot/support housing to the table at any desired bevel angle.
Saws and other apparatuses designed for cutting or performing other working operations on a workpiece typically require adjustment mechanisms for moving the saw blade or cutting tool into an angular relationship to the workpiece. Examples of such equipment include crosscut compound miter saws which are adapted for allowing the user to selectively move the saw blade into any of a number of positions or modes for square cutting, miter cutting, bevel cutting, or compound miter cutting where a combination miter angle and bevel angle are cut. In addition, some operations, such as dado cutting or shaping operations, for example, require the use of saw blades or other cutting or working devices of different shapes or sizes to be substituted for one another in order to perform the desired operation on the workpiece, whether the workpiece is composed of wood, plastic, metal other materials.
In order to allow for the adjustment in the miter and the bevel angle, the saw blade, cutter or other working device is angularly adjustable with respect to a horizontal base and a vertical fence against which the workpiece is positioned. The miter adjustment allows the saw blade, cutter or other working device to move angularly with respect to the vertical fence while maintaining perpendicularity with the horizontal base. The bevel adjustment allows the saw blade, cutter or other working device to move angularly with respect to the horizontal base while maintaining perpendicularity with the vertical fence. At times it may be desirable to cut a combination miter angle and bevel angle by simultaneously adjusting the angularity of the blade with respect to both the horizontal base and the vertical fence.
Once the saw blade, cutter or other working device has been adjusted to the desired position with respect to the horizontal base and the vertical fence, locking mechanisms for the miter and bevel adjustment must be activated in order to prohibit movement of the saw blade, cutter or other working device with respect to the base and fence while the cutting operation is performed. These locking mechanisms need to be easily activated, adjustable and quick acting in order to optimize the efficiency of the cutting apparatus and provide convenience to the operator of the apparatus.
In accordance with the present invention, an improved bevel locking mechanism is employed. The locking mechanism includes a base or table assembly having an axially extending locking rod and a bevel support housing disposed on the locking rod such that the housing can move axially along the rod as well as pivot on the rod. The axial movement permits the locking of the housing to the base and the pivoting movement permits the desired adjustment to the bevel angle. A cam is positioned on the rod adjacent to the housing such that it can move axially on the rod but it is not allowed to rotate with respect to the rod. The double cam includes an angular cam surface which abuts a second angular cam surface located on a locking handle. The locking handle is positioned on the rod adjacent the cam such that it cannot move axially on the rod in a direction away from the cam but it is free to rotate with respect to the rod.
When the two cam surfaces are aligned, the support housing can be pivoted on the rod in order to adjust the bevel angle. Once the desired bevel angle has been attained, the locking handle is rotated on the rod mis-aligning the two camming surfaces resulting in the axial movement of the support housing into engagement with the base or table assembly, locking the support housing to the base. The adjustment to the locking mechanism is achieved by rotating a locknut which axially locates and secures the various components on the locking rod.
Other advantages and objects of the present invention will become apparent to those skilled in the art from the subsequent detailed description, appended claims and drawings.